The F1 chief executive, however, admitted that after the Spaniard’s four days in hospital, he is not surprised the new McLaren-Honda driver is sitting out Melbourne.

“What has surprised me is what happened (in Barcelona). It is completely inexplicable, for him as well,” Ecclestone is quoted by DPA news agency and multiple Spanish publications.

“Fernando is a little surprised by what has happened to him.”

Amid wild speculation about the cause of the crash and Alonso’s medical condition, the 84-year-old Briton said the FIA is now looking into it.

“McLaren doesn’t want to discuss it, so there’s not much we can do,” said Ecclestone.

“It is really a sporting issue. So maybe it is one of those things that is necessary for the FIA to investigate.”

Indeed, twelve days after the Barcelona incident, the questions are growing by the hour.

Britain’s Mirror newspaper said FIA investigators have not ruled out that Alonso lost consciousness before crashing, which would either indicate something like an electric shock or a pre-existing health condition.

Former F1 doctor Gary Hartstein said the mystery would grow deeper if Alonso also sits out Malaysia.

“That would be head-scratching time, for sure,” he told the BBC.

“It would be highly unusual — so much so that they’d have to say something. But for now concussion is the most likely and it explains everything we know at the moment,” said Hartstein.

Italy’s Omnicorse claims Alonso is currently wearing a device in his mouth to help with Temporomandibular pain.

The Temporomandibular joint connects the jaw to the skull and problems are reportedly often associated with head or neck issues.

“The important thing is that he’s fine,” said Sebastian Vettel on Thursday.

“Of course it’s a shame that he cannot drive, but I believe the speculation does not help.

“He suffered a concussion and it is quite normal to avoid any risk,” said the Ferrari driver.

As for Alonso’s crash, Vettel said: “I was right behind him, but I was too far away to be able to see exactly how the accident occurred.

“I only saw the last part of it, but the crash itself did not look so dramatic. But it was obviously a shock to hear that he was unconscious.”

F1 legend Alain Prost, meanwhile, told Spain’s Marca sports daily: “I only know what I’ve seen or read so I don’t know what happened — only a few people do.

“I have no view about it, just that the communications have been strange but I do not want to make judgements. The most important thing is that he is fine,” the Frenchman added.